To ensure effectiveness in reaching organizational goals, authorities must gain legitimacy (i.e., the support and approval of their subordinates). This study uniquely brings together an identity-based approach, stressing an authority’s use of fair decision-making procedures, a resource-based approach, highlighting an authority’s use of power in a benevolent fashion, and the status of the authority (represented by workplace experience) as sources of legitimacy. We argue that assessments of the nature of the authority’s behaviors and experience—whether they enhance interactional justice and/or engender trust, thereby signaling positive social relationships—mediate the direct effects of the sources. Adult study participants (404 males, 403 females) read one of eight vignettes in which we factorially combined two levels of each proposed antecedent. Questionnaire items measured perceived interactional justice, trust, and legitimacy. Results from structural equation modeling show that procedural justice, benevolent power use, and the authority’s workplace experience exert positive effects on the perceived legitimacy of the manager and on assessments of interactional justice and trust, which ultimately mediate the direct pathways to legitimacy. These findings highlight the nature of actions important to helping members of groups not typically holding positions of authority (e.g., women and minorities) to gain legitimacy and ensure effectiveness.